PURIFICATION OF EXOINULINASE BIFIDOBACTERIUM BREVE (PEMURNTAN EKSOINULINASE DARI BIFIDOBACTERIUM BREVE)

ABSTRACT Extracellular exoinulinase was produced from Bifidobacterium breve in media with inulin as the only C-source. The enzyme was purified on DEAE-Sephadex A-50, preparative IEF and gel filtration yielded a purification of 68-fold. The pI range was from 4.2 to 4.9, the molecular weight was identified using polyacrylamide gel electrophoresis (SDS-PAGE) and the result was 6459 and 32 kD. It did not hydrolyse inulin into smaller fructan units or sucrose, therefore it was characterized as an exo-type enzyme. Key words: Bifidobacterium, exoinulinase, inulin ABSTRAK Eksoinulinase ekstraseluler dihasilkan dari Bifidobacterium breve dalam media inulin sebagai satu¬satunya sumber karbonnya. Enzim dimurnikan menggunakan DEAE Sephadex A-50, IEF Preparative, filtrasi gel, dan diperoleh kemurnian 68 kali. Harga pI yang diperoleh berkisar dari 4,2 sampai 4,9 dengan massa molekul berturut-turut: 64, 59 dan 32 kD yang diuji dengan poliacrilamide gel elektroforesis (SDS-PAGE). Enzim tidak dapat menghidrolisis inulin kedalam unit-unit fruktan atau sukrosa, sehingga diperoleh suatu kesimpulan bahwa ensim tersebut dikarakterisasikan sebagai tipe eksoensim. Kata Kunci: Bifidobacterium, eksoinulinase, inuli

E11E_{11}, SL(32) and Central Charges

We show that the $E_{11}$ representation that contains the space-time translation generators also contains the rank two and five totally anti-symmetric representations of $A_{10}$. By studying the behaviour of these latter $A_{10}$ representations under SL(32), which we argue is contained in the Cartan involution invariant sub-algebra of $E_{11}$, we find that the rank two and five totally anti-symmetric representations must be identified with the central charges of the eleven dimensional supersymmetry algebra.Comment: 12 pages, plain tex, Typos corrected, one reference and three sentences added and equation (3.8) change

Master Canonical Action and BRST Charge of the M Theory Bosonic Five Brane

A complete analysis of the canonical structure for a gauge fixed PST bosonic five brane action is performed. This canonical formulation is quadratic in the dependence on the antisymmetric field and it has second class constraints. We remove the second class constraints and a master canonical action with only first class constraints is proposed. The nilpotent BRST charge and its BRST invariant effective theory is constructed. The construction does not assume the existence of the inverse of the induced metric. Singular configurations are then physical ones. We obtain the physical Hamiltonian of the theory and analyze its stability properties. Finally, by studying the algebra of diffeomorphisms we find under mild assumptions the general structure for the Hamiltonian constraint for theories invariant under 6 dimensional diffeomorphisms and we give an algebraic characterization of the constraint associated with the bosonic five brane action. We also identify the constraint for the bosonic five brane action upgraded with a cosmological term, it contains a Born-Infeld type term.Comment: 33 pages, LaTeX, typos corrected, references adde

E_11: Sign of the times

We discuss the signature of space-time in the context of the E_11 -conjecture. In this setting, the space-time signature depends on the choice of basis for the ``gravitational sub-algebra'' A_10, and Weyl transformations connect interpretations with different signatures of space-time. Also the sign of the 4-form gauge field term in the Lagrangian enters as an adjustable sign in a generalized signature. Within E_11, the combination of space-time signature (1,10) with conventional sign for the 4-form term, appropriate to M-theory, can be transformed to the signatures (2,9) and (5,6) of Hull's M*- and M'-theories (as well as (6,5), (9,2) and (10,1)). Theories with other signatures organize in orbits disconnected from these theories. We argue that when taking E_11 seriously as a symmetry algebra, one cannot discard theories with multiple time-directions as unphysical. We also briefly explore links with the SL(32,R) conjecture.Comment: 20 pages, LaTeX, 1 figure; v2. typo's corrected, references adde

Hidden Spacetime Symmetries and Generalized Holonomy in M-theory

In M-theory vacua with vanishing 4-form F, one can invoke the ordinary Riemannian holonomy H \subset SO(1,10) to account for unbroken supersymmetries n=1, 2, 3, 4, 6, 8, 16, 32. However, the generalized holonomy conjecture, valid for non-zero F, can account for more exotic fractions of supersymmetry, in particular 16<n<32. The conjectured holonomies are given by H \subset G where G are the generalized structure groups G=SO(d-1,1) x G(spacelike), G=ISO(d-1) x G(null) and G=SO(d) x G(timelike) with 1<=d<11. For example, G(spacelike)=SO(16), G(null)=[SU(8) x U(1)] \ltimes R^{56} and G(timelike)=SO*(16) when d=3. Although extending spacetime symmetries, there is no conflict with the Coleman-Mandula theorem. The holonomy conjecture rules out certain vacua which are otherwise permitted by the supersymmetry algebra.Comment: Notes added addressing Hull's results in hep-th/0305039. We agree with the necessity of SL(32,R) for classifying generalized holonomy. References added. 18 pages, late

A Brane Teaser

In this note we study the puzzle posed by two M5-branes intersecting on a string (or equivalently, a single M5-brane wrapping a holomorphic four-cycle in C^4). It has been known for a while that this system is different from all other configurations built using self-intersecting M-branes; in particular the corresponding supergravity solution exhibits various curious features which have remained unexplained. We propose that the resolution to these puzzles lies in the existence of a non-zero two-form on the M5-brane world-volume.Comment: 21 pages. References adde

BPS Solitons in M5-Brane Worldvolume Theory with Constant Three-Form Field

We study BPS solutions for a self-dual string and a neutral string in M5-brane worldvolume theory with constant three-form field. We further generalize such solitons to superpose with a calibrated surface. We also study a traveling wave on a calibrated surface in the constant three-form field background.Comment: 12 pages, LaTeX, minor correction, added referenc

Dynamics of Weyl Scale Invariant non-BPS p=3 Branes

In this paper a Weyl scale invariant $p=3$ brane scenario is introduced, with the brane embedded in a higher dimensional bulk space with $N=1, 5D$ Super--Weyl symmetry. Its action, which describes its long wave oscillation modes into the ambient superspace and breaks the target symmetry down to the lower dimensional Weyl W(1,3) symmetry, is constructed by the approach of coset method.Comment: 12 pages, modified versio

N=2 supersymmetric AdS_4 solutions of M-theory

We analyse the most general N=2 supersymmetric solutions of D=11 supergravity consisting of a warped product of four-dimensional anti-de-Sitter space with a seven-dimensional Riemannian manifold Y_7. We show that the necessary and sufficient conditions for supersymmetry can be phrased in terms of a local SU(2)-structure on Y_7. Solutions with non-zero M2-brane charge also admit a canonical contact structure, in terms of which many physical quantities can be expressed, including the free energy and the scaling dimensions of operators dual to supersymmetric wrapped M5-branes. We show that a special class of solutions is singled out by imposing an additional symmetry, for which the problem reduces to solving a second order non-linear ODE. As well as recovering a known class of solutions, that includes the IR fixed point of a mass deformation of the ABJM theory, we also find new solutions which are dual to cubic deformations. In particular, we find a new supersymmetric warped AdS_4 x S^7 solution with non-trivial four-form flux.Comment: 50 pages, 2 figures; v2: typos fixed, some intermediate formulas added to improve clarity, references adde

Non-conventional yeast species for lowering ethanol content of wines

Rising sugar content in grape must, and the concomitant increase in alcohol levels in wine, are some of the main challenges affecting the winemaking industry nowadays. Among the several alternative solutions currently under study, the use of nonconventional yeasts during fermentation holds good promise for contributing to relieve this problem. Non-Saccharomyces wine yeast species comprise a high number or species, so encompassing a wider physiological diversity than Saccharomyces cerevisiae. Indeed, the current oenological interest of these microorganisms was initially triggered by their potential positive contribution to the sensorial complexity of quality wines, through the production of aroma and other sensory-active compounds. This diversity also involves ethanol yield on sugar, one of the most invariant metabolic traits of S. cerevisiae. This review gathers recent research on non-Saccharomyces yeasts, aiming to produce wines with lower alcohol content than those from pure Saccharomyces starters. Critical aspects discussed include the selection of suitable yeast strains (considering there is a noticeable intra-species diversity for ethanol yield, as shown for other fermentation traits), identification of key environmental parameters influencing ethanol yields (including the use of controlled oxygenation conditions), and managing mixed fermentations, by either the sequential or simultaneous inoculation of S. cerevisiae and non-Saccharomyces starter cultures. The feasibility, at the industrial level, of using non-Saccharomyces yeasts for reducing alcohol levels in wine will require an improved understanding of the metabolism of these alternative yeast species, as well as of the interactions between different yeast starters during the fermentation of grape must.Experimental work by researchers from ICVV is supported by the Spanish Government trough MINECO and FEDER funds: MINECO AGL2012-32064 and AGL2015-63629-R grants, INIA RM2012-00007-00-00 grant, MINECO RTC-2014-2186-2 grant, MINECO training contract for AR, MINECO Formación Postdoctoral contract for JC. Experimental work by the authors from Polytechnic University of Marche is supported by Ricerca Scientifica di Ateneo RSA2015.Peer Reviewe